Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: The Water Activity of a Novel Bioherbicide Product Affects Shelf Life

Authors
item Connick Jr, William
item Daigle, Donald
item Williams, Kelley - DELTA STATE UNIVERSITY
item Vinyard, Bryan
item Boyette, Clyde
item Quimby Jr, Paul

Submitted to: American Laboratory
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 15, 1996
Publication Date: N/A

Interpretive Summary: Optimization of shelf life is critically important for biocontrol products containing living microorganisms. Spores of Colletotrichum truncatum, a fungal pathogen of the weed, hemp sesbania, were formulated in wheat flour-kaolin granules ("Pesta"). Granules were conditioned at various water activities during storage at 25 C over desiccant or saturated salt solutions. The best shelf life resulted with samples at a water activity of 0.13 (13% relative humidity), and this gave 87% viability after one year.

Technical Abstract: Optimization of shelf life is critically important for biocontrol products containing living microorganisms. Spores of Colletotrichum truncatum, a fungal pathogen of the weed, hemp sesbania, were formulated in wheat flour-kaolin granules ("Pesta"). Granules were conditioned at water activities of 0.04, 0.13, 0.35, 0.51, and 0.74 during storage at 25 C over desiccant or saturated salt solutions. The best shelf life resulted with samples at a water activity of 0.13 (13% relative humidity), and this gave 87% viability after one year. Shelf-stable and effective biocontrol products will offer an alternative to chemical pesticides in some agricultural applications. Pesta that contains safe, biodegradable, agricultural commodity ingredients is a promising addition to biocontrol agent formulation technology.

Last Modified: 9/20/2014
Footer Content Back to Top of Page